Have you ever watched a worm move? They don't move very fast, do they? Unless they're in the belly of a bird — a place no worm wants to be! — they don't fly south for the winter. It's also highly unlikely that they drive or take the bus. So where do they go in the winter?

The answers to these questions depend in part on what type of worm you're talking about. There are a lot of different types of worms. Would you believe there are over 4,400 different species of worms around the world? It's true!

Of those thousands of types of worms, over 2,700 of them are species of earthworms. Only a fraction of those can be found in the United States. Still, American gardens are called home by at least 30 different types of earthworms.

Some earthworms choose to live their whole lives in the ground's upper layer of soil and leaves. These earthworms never burrow deep into the soil, so cold winter temperatures kill them.

To keep their species alive, however, they lay eggs in tiny sacks that protect the eggs from freezing or drying out during the winter. In the spring, the eggs hatch and a whole new group of worms is born to repeat the life cycle.

Other earthworms, such as the night crawlers often used as fish bait, live close to the surface in warm weather and down deep in cold weather. When winter hits, these worms burrow down below the frost line.

The frost line — sometimes called frost depth or freezing depth — is the depth at which the groundwater in soil usually freezes in winter. The frost line varies based upon climatic conditions. It can usually be estimated based upon latitude. The farther north you travel, the deeper the frost line.

In the United States, the frost line ranges from zero feet (in warm areas like Florida) to six feet or more (in cold areas like Alaska). To survive freezing cold temperatures, worms must burrow to an area below the frost line wherever they live.

Night crawlers, for example, can burrow to depths of six feet or more. When they burrow down below the frost line, they nest in small chambers at the bottom of the tunnels they dig. Since worms can't breathe if their skin dries out, they coat the sides of their nesting chambers with a slimymucus to keep them moist through the winter.

Once worms burrow far enough underground, the soil stays at a fairly constant temperature that keeps the worms warm through the winter. This warmer soil down deep acts like a warm blanket and insulates the worms from the cold.

Night crawlers don't really hibernate like some animals do in the winter. If there is a warm spell during the winter, night crawlers will occasionally come back up to the surface for a while until it gets cold again. When spring returns, worms make their way back to the surface.

Wonder Contributors

We’d like to thank:

Jennifer and David for contributing questions about today’s Wonder topic!

Did you get it?

Wonder What's Next?

Tomorrow’s Wonder of the Day is sure to make you smile!

Try It Out

Are you ready to learn more about worms? Be sure to dig into the following activities with a friend or family member:

Pick a spot in your backyard to dig for worms. Grab a shovel or similar tool and dig down until you find some worms. Can you tell what kind they are? Do you think they lay eggs or dig down deeper to hibernate in winter? Spend some time observing how the worms behave in their native soil. When you're finished, be sure to return them to their home and recover them with soil!

Ready to hibernate? If it's cold where you live, you might think that hibernating sounds good about now. What do you like to do when it gets cold outside? We like to snuggle up under a thick blanket and sip hot cocoa while we watch favorite movies with our family. What types of things does your family do when the weather outside turns frigid?

Did you know that you can help your parents save money and keep your house warmer during the winter? It's true! Here are a few simple things that you can help your family do to make your house cozy during the long winter months: + Make sure all the windows and doors in your home are fully closed. + Keep cold air from seeping in under doors by making homemade door draft snakes! + Help turn off all outdoor water sources to prevent the pipes in your house from freezing. + Keep the warm air inside your house by closing blinds and curtains over windows.

Wonderopolis

Mrs. Olson's Class

Oct 22, 2012

We are learning about Worms in our class. We don't know if this is a fact or fictional tale... Can a worm still live even though they get cut? We WONDER if having 5 hearts might be a factor in keeping it alive?

Wonderopolis

Oct 22, 2012

WOW, we are so happy to hear that the WONDERful students in Mrs. Olson's class are WONDERing about worms! How FUN! :)
Worms can survive is part of their body becomes detached-- it's called "regeneration." We Wonder if you can do some research of your own to find out how these worms can regenerate! We are very proud of all our Wonder Friends today! :)

Team McNeil20

Apr 1, 2012

Hi wonderopolis! I have learned so much about where worms go in the winter. Worms are a lot more interesting then I thought they were. I learned that there are 4,400 different species of worms around the world. I also learned that where worms go in the winter depends on the type of worm. The coolest fact I learned though was that to keep their species alive by laying their eggs in tiny sacks that protect them from freezing or drying in the hot or frigid weather. One question I have is why some worms choose to live their whole life on the upper layer of soil and the cold weather ends up killing them?
Thank you Wonderopolis!

Wonderopolis

Apr 1, 2012

WOW! You sure learned a lot about worms today, Team McNeil 20! We think that's AWESOME! We really like your question about why certain worms live the way they do, too! Nature is a FUN thing to WONDER about, isn't it? :-)

Mr. Flinn's Kindergarten Class...

Mar 7, 2012

My students had so much to say about this Wonder. They either wanted to write about what they learned or stories about worms. We decided to blog about it! Please feel free to leave a comment for the students. http://kidblog.org/MrFlinnsClass/

kaitlyn kennedy

Wonderopolis

Mar 5, 2012

Thanks for leaving us another great comment, Kaitlyn! We appreciate that you are exploring several Wonders in Wonderopolis today! Some worms lay eggs and some worms dig deeper into the ground for the winter...so, you are right on both points! Way to go! :-)

Rylie

Feb 28, 2012

Hello Wonderopolis,
I didn't know that there are so many earthworms. I like to go fishing ......sometimes. Once I caught a pregnant catfish, it went back in the lake. I have a wonder for you, WHERE DO FRUIT GET THERE COLOR?
Sincerly
Rylie

Wonderopolis

Feb 29, 2012

That's a really cool story about catching a pregnant catfish, Rylie! We bet she was super thankful to be released back into the lake! Thanks for sharing your idea for a future Wonder of the Day®, too...we think it's GREAT! Did you know there are LOTS of Wonders about FRUIT? Check them out by clicking on this link: http://wonderopolis.org/category/fruit/. Happy WONDERING! :-)

McPherson's Fourth Grade Class

Wonderopolis

Feb 28, 2012

Hello, McPherson’s Fourth Grade Class! We think it's GREAT that you guys have differing opinions about worms! Thanks so much for letting us know you thought today's Wonder was interesting...that makes us super happy! :-)

Wonderopolis

Sandi in MN

Feb 28, 2012

We like to snuggle under a warm blanket and read books when it's cold outside. If it's not too cold, we also bundle up and play in the snow! Sledding is one of our favorite activities. We also like ice skating, snow shoeing and skiing. We're just glad we don't have to burrow six feet down like the earth worm does. :)

Missy Tepe

Feb 28, 2012

I don't use worms for fishing bait. Instead, I use hot dogs because hot dogs are really good bait for fishing because the second time I ever went fishing, I caught a huge large-mouth bass! Just remember, always use the skins of a hot dog for bait. Do you have any wonders about fishing? If so, please send a link in your comment back!
P.S I think tomorrow's wonder is about Leap Year.

Wonderopolis

Feb 28, 2012

Thanks so much for sharing your worm-saving way to fish, Missy! That's really AWESOME that you caught a bass...how cool! We don't have any wonders about fishing, but we have some great ones about FISH! Check these out:
Wonder #18 - Can You Train a Goldfish? http://wonderopolis.org/wonder/pavlovs-fish/
Wonder #38 - Why Do Catfish Have Whiskers? http://wonderopolis.org/wonder/why-do-catfish-have-whiskers/
PLUS! There's even one about HOTDOGS!
Wonder #273 - How Many Hot Dogs Can You Eat In 10 Minutes? http://wonderopolis.org/wonder/how-many-hot-dogs-can-you-eat-in-10-minutes/
:-)

Wonderopolis

I think worms go in the ground during winter. They hibernate, which means they sleep. I think they sleep for seven hours. When they are awake, they stay in the ground, but they eat. I think they like to eat apples, bananas, blueberries oranges, including the peels. For fun, worms like to go for long walks even though they don't have legs. They also like to crawl. They do not like fishing! Who wants to be bait?! If they want to, worms can get married. This keeps them out of trouble.

Little Helper

Wonderopolis

2/3 Class--New Century School-...

Feb 28, 2012

Here are some of our thoughts and questions about worms:
1. How do worms form their mucus?
2. What is mucus?
3. How thick is a frost line?
4. How deep down is Wisconsin's frost line?
5. How do worms not get cut in half since their bodies are so thin and rocks are so sharp?
6. Does where the frost line is depend upon how cold it is?
7. How do worms dig so fast?
8. I think worms eat the dirt (for how they dig).
Now, here are some of our predictions about tomorrow's Wonder of the Day:
1. How leap days are made?
2. Who created February 29.
3. Why does February have only 29 days.
4. It might be about sports--the Brewers play the Yankees every four years.

Wonderopolis

Feb 28, 2012

WOW, 2/3 Class--New Century School--Verona, WI! You guys REALLY did some great extra WONDERing about worms today...we're SUPER proud of you! We'd really like to know the answers to some of those AWESOME questions you guys came up with, too! We also want to say, "high five!" for sharing those predictions about tomorrow's Wonder! We can't wait to visit Wonderopolis tomorrow to see if you guys were correct about one or more of them! :-)

Mrs. Rist's 2nd Grade Class

Feb 28, 2012

We learned a lot about worms! Last week, we read a book called Wiggling Worms at Work where we learned a little about earthworms. From reading that book, we learned about underground tunnels and chambers. You helped us learn more about worms! We did not know that worms coat their tunnels with mucus to keep them moist. We also did not know that there were 4,400 different species of worms!!! Wow!!!! Thank you Wonderopolis! We love Wonderopolis! :)

Wonderopolis

Feb 28, 2012

Well, we LOVE receiving comments like yours, Mrs. Rist’s 2nd Grade Class! We really enjoy hearing all the cool things our Wonder Friends learn when they visit a Wonder of the Day® together! Thank you for letting us know what YOU learned today and also for sharing that you had some background knowledge about worms before you explored today's Wonder! :-)

Wonderopolis

Austin Cannaday

Feb 28, 2012

Hey guys, it's me coming to say that earthworms are cool and nightcrawlers are creepy. But, anyway, I always go fishing in the Summer, Fall, Winter, and the Spring. Hope that didn't sound weird. This website is really cool. I get on whenever I am told or if I want to, but I don't comment all the time because sometimes I get short on time or I never finish the comment. Well, anyway like Amoolya said, I think tomorrow's wonder is going to be about a Leap year. Bye.

i dont lik this

Wonderopolis

Wonderopolis

Feb 28, 2012

We don't think that sounded weird at all, Austin! We think it sounded like a Wonder Friend who has something cool to say about worms and LOVES to go fishing! We think that ROCKS, actually! Thanks for visiting today's Wonder! :-)

amoolya

Wonderopolis

Feb 28, 2012

Hi, Amoolya! We think it's GREAT that you are the very first Wonder Friend to comment on today's Wonder about WORMS! Thanks for letting us know what you think tomorrow's Wonder might be about, too! :-)

Mattha

Jan 18, 2014

Wow! Today I'm trying to fish with my precious grandchildren, but we have only found a few skinny worms. We live in Central Mississippi but it has been really cold , and it was 27 F last night. I think we are going to have to go buy some crickets! Thanks for the GREAT information about worms! So glad I found your site!